Adam Lanza's Father a 'Broken Man' 1 Year After Newtown School Slaughter

Peter Lanza, the father of Newtown school shooter Adam Lanza remains a "broken" man who still isn't able to deal with what his son did last Dec. 14, his sister-in-law says.

"Peter is a changed man," Marsha Lanza told MailOnline in a story published Friday. "He's broken. How can you ever begin to try and deal with that? It's just impossible."

The elder Lanza, who works as a tax accountant, had not been in contact with his troubled son for two years before he killed his mother, Nancy, before heading to the Sandy Hook Elementary School, where he murdered 20 first-graders and kindergarten students.

Marsha Lanza said that her brother-in-law has only spoken about the horrific incident to "a very, very small number of people, including my husband Michael, his brother, as they are very close."

She said the shootings are still also too much for her own husband "and sometimes he tells me not to ask about it."

She said that the shootings also affect the rest of the family when people recognize the Lanza name.

"It happens everywhere, the bank, restaurants, gas stations," she said. "You see them see the name, ask for your ID and then you know what they’re thinking. I know what’s going through their mind."

A report from Connecticut prosecutors says there is still no clear motive for the shootings, reports The Washington Post.

It indicated Peter Lanza and his younger son had enjoyed regular contact, including hiking, playing video games and shooting guns, until 2010, when their relationship fell apart.

Peter was divorced from Adam Lanza's mother in 2001, and she got sole custody of the boy, who suffered from Asperger's Syndrome.

According to a report from the Danbury Attorney General last week, she and her son did not speak for three months, even though they shared the same house, and she was banned from going into his room, where he not only kept the weapons he used in the school shootings, but a huge, 7 ft. by 4 ft. poster on a wall that detailed the top 500 mass killings of all time.

Adam's older brother, Ryan, who was initially implicated in the shootings after his identification was found at the scene, continues to refuse comment about the incident, said MailOnline.

Marsha Lanza said the family is still deeply traumatized and asking if there was something more that could have been done.

"Did we miss the signs?" she said. "I went over old Facebook messages that Nancy sent me at the time and nothing seemed to indicate this was coming. We're still struggling to understand it ourselves.'